Question: If $x \veebar y = x-4y$ and $x \star y = 3x-8$, find $(-5 \star 6) \veebar -5$.
First, find $-5 \star 6$ $ -5 \star 6 = (3)(-5)-8$ $ \hphantom{-5 \star 6} = -23$ Now, find $-23 \veebar -5$ $ -23 \veebar -5 = -23-(4)(-5)$ $ \hphantom{-23 \veebar -5} = -3$.